This invention pertains to the art of cutting tools, and more particularly to a boring tool or reamer. The invention is particularly applicable to those tools in which a cutting element or blade is adjustable relative to the remainder of the cutting head and will be described with particular reference thereto. However, it will be appreciated that the invention has broader applications and may be advantageously employed in still other environments and applications.
Precision cutting of a workpiece for providing a close tolerance bore, chamfer, groove, etc. is well known in the art. A rotary cutting tool such as a reamer is typically used to cut the workpiece. Selective control of the position of the cutting tool relative to the workpiece is provided by a numerical processor controller, for example, as shown and described in U.S. Pat. No. 4,250,775. Particular details of the positional control of the cutting tool form no part of the subject invention so that further discussion herein is deemed unnecessary.
Secured to a rotating spindle of the cutting tool is a head that incorporates one or more cutting blades or inserts. The blades extend radially outward from the rotational axis of the cutting head and are set at a predetermined angle relative to the workpiece to provide a desired cut. As will be understood, the location of the edge of the cutting blade must be carefully controlled and is subject to wear, thereby requiring periodic adjustment and replacement. Many prior art arrangements employ an adjustable wedge-shaped member that engages a portion of the cutting blade. The wedge is advanced or retracted through suitable threaded adjustment members to locate and clamp a base portion of the cutting blade as desired. In fact, these arrangements oftentimes include plural, axially spaced adjustment wedges or clamp jaws that require an inordinate amount of time to adjust the blade for a desired cutting operation.
As will be understood, any downtime associated with replacing or adjusting a cutting blade is necessarily undesirable. Moreover, multiple adjustment members compound the adjusting procedure and require repeated measuring steps since adjustment of one portion of the blade effects the location of the remainder of the blade. Continued minute adjustment eventually results in an accurate location or position of the blade but not without associated expense of tool downtime. Multiple gages and fixtures are often necessary to complete setup and adjustment of known rotary cutting tool arrangements. In still other arrangements, an entire tool must be replaced.
Still other adjustable cutting blade arrangements provide inadequate support for the cutting blade. Inadequate blade support can lead to a number of problems. For example, premature blade wear may result. Inconsistent cutting pressure and poor tool performance are still other potential problems associated with insufficient blade support.
Minimizing the amount of time required for setup and adjustment, while maintaining adequate support for the cutting blade are competing concerns that have not been adequately addressed by prior art arrangements. Accordingly, it has been desired to provide an easily adjustable, highly accurate, and fully supported adjustable cutting blade arrangement that meets the various needs of the rotary cutting tool industry.